The present invention relates generally to apparatus for insulating hydrocarbon production equipment in a subsea environment. More specifically, the present invention relates to apparatus for insulating subsea connectors for flowlines, jumpers, umbilicals, and other tubular members.
Production equipment, such as manifolds and trees, that are used in producing oil and gas in a subsea environment are usually interconnected by flowlines, or other tubulars. The flowlines provide fluid communication to support the flow of production fluids, control fluids, and other fluids. In the subsea environment, the equipment is often exposed to temperature at or only slightly above the freezing point of water.
Although the fluids extracted from subsea wells are often at an elevated temperature when leaving the well, the fluids can cool as they move through the production equipment and flowlines. This cooling is especially problematic during an interruption in flow where temperatures can decrease to a point where flow will be impeded, such as by the formation of hydrates. In order to decrease the rate at which the fluid cools, thermal insulation is often installed on and around the production equipment and flowlines.
One area of difficulty in providing thermal insulation is at the connections between the production equipment and the flowlines. The flowlines are typically installed after the production equipment is on the seabed, with the connections between the flowlines and the production equipment made by remotely operated vehicles (ROV) or some other remotely operated device. Therefore, any thermal insulation must allow for remotely controlled installation of the connector or be able to be installed after the connection is made.
Insulation used in subsea environments must be able to withstand the high hydrostatic pressures found in deep water applications. Conventional insulation used for subsea systems provides very little compressibility so as to better withstand hydrostatic pressure. When installing insulating systems subsea, water often becomes trapped by the insulation. When this water is heated it expands and may tend to damage the insulation or create circulation paths for cold water to seep under the insulation.
Thus, there remains a need to develop methods and apparatus for thermally insulating flowline connectors, which overcome some of the foregoing difficulties while providing more advantageous overall results.